1. Field of the Invention
The present invention relates to a drive current supply circuit.
2. Description of the Related Art
Drive current supply circuits have been developed for laser diodes in optical pickups. Prior art drive current supply circuits are disclosed in published Japanese Patent No. H. 7-31823 and U.S. Pat. No. 5,898,334. The drive current to the laser diode in an optical pickup is different during writing to the storage medium and during reading, being set to a larger value during writing. The drive current supply circuits described above are effective when the drive current is to be made variable.